Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare idempotentHint=true and destructiveHint=false, so 'Idempotent — no-op if already in the group' largely restates structured data. It does clarify what idempotency means here, which is mildly useful, but it omits permission requirements, behavior when the group or document does not exist, and append semantics.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two short sentences with zero waste, and the core action is front-loaded before the idempotency note. Nothing extraneous.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Output schema and annotations are present, so safety and return values are covered elsewhere. However, for a mutation tool this leaves gaps the description should fill — such as whether the group must pre-exist, what happens on a bad document_id, and whether this affects group ordering or counts.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100% and the tenant_slug parameter carries a detailed fallback explanation in the schema itself, so the description adds nothing beyond it. Baseline 3 is appropriate when the schema does the heavy lifting.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb+resource: 'Add a document to a group', which maps directly onto the tool name and is unambiguous. It does not name its natural counterpart (kb_groups_detach_document) or distinguish itself from other group tools, but the core action is clear.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Usage is implied by the verb phrase — you call this to associate an existing document with a group — but there is no explicit when-to-use, no prerequisites (e.g. group must exist), and no guidance on when to reach for the detach sibling instead.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.